Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
The electrocaloric effect (ECE) is a phenomenon in which a material shows a reversible entropy change under an applied electric field. Any material capable of producing ECE is referred to herein as an electrocaloric material. The entropy change in an electrocaloric material may correspond to a temperature change in the electrocaloric material in an adiabatic environment, or may cause the electrocaloric material to absorb or release heat from surroundings in diabatic environments. When an electric field is applied to an electrocaloric material, it induces a change in net electric polarization within the electrocaloric material, which leads to changes in entropy. The electrocaloric effect is characterized by entropy changes occurring with heat transfer in the electrocaloric material.
Electrocaloric materials have been a focus of scientific interest for several decades. Current literature discloses ECE in perovskite ferroelectric ceramics, which exhibit ECE most pronounced at their transition temperatures above 200° Celsius (° C.). In 2006, thin films of lead zirconate titanate (PZT) were reported to show ECE cooling of 12° C., with an electric field change of 4.8×107 volts/meter (V/m) at an operational temperature of around 220° C. (A. S. Mischenko et al., “Giant Electrocaloric Effect in Thin-Film PbZr0.95Ti0.05O3”, Science 311 (2006) 1270-1271. In 2008, a ferroelectric copolymer of PVDF was shown to achieve around 12° C. at an operating temperature of 70° C. (Bret Neese, et al., “Large Electrocaloric Effect in Ferroelectric Polymers near Room Temperature”, Science 321 (2008) 821-823; and S. G. Lu and Q. Zhang, “Electrocaloric Materials for Solid State Refrigeration”, Adv. Mater. 21 (2009) 1-5.)
Techniques of the present disclosure may be utilized in cooling systems and other thermal transfer devices using electrocaloric materials. The present disclosure may provide further related advantages.